def test_basics(self):
W = 102
D = 1010
K = 11
alpha = .27
eta = 3.1
model = OnlineLDA(num_words=W,
num_topics=K,
num_documents=D,
alpha=alpha,
eta=eta)
self.assertEqual(K, model.num_topics)
self.assertEqual(K, model.alpha.size)
self.assertEqual(D, model.num_documents)
self.assertEqual(W, model.num_words)
self.assertEqual(alpha, model.alpha.ravel()[randint(0, K - 1)])
self.assertEqual(eta, model.eta)
with self.assertRaises(RuntimeError):
model.alpha = random.rand(K + 1)
alpha = random.rand(K, 1)
model.alpha = alpha
self.assertLess(max(abs(model.alpha.ravel() - alpha.ravel())), 1e-20)
def test_lower_bound(self):
W = 100
K = 22
D = 30
N = 60
# generate random vocabulary
vocab = [
''.join(
choice(ascii_letters) for _ in range(5 + random.randint(10)))
for _ in range(W)
]
model0 = ReferenceLDA(vocab, K, D, 0.1, 0.3, 1024., 0.9)
model1 = OnlineLDA(num_words=W, num_topics=K, num_documents=D)
model1.alpha = model0._alpha
model1.lambdas = model0._lambda
# generate D/2 random documents of average length N
docs1 = model1.sample(D // 2, N)
docs0 = [zip(*doc) for doc in docs1]
# estimate lower bound
elbo1 = model1.lower_bound(docs1)
elbo0 = model0.approx_bound(docs0)
# estimate should deviate less than 1% from reference estimate
self.assertLess(abs(elbo1 - elbo0) / abs(elbo0), 0.01)
def test_empirical_bayes_alpha(self):
model = OnlineLDA(num_words=4,
num_topics=2,
num_documents=1000,
alpha=[.2, .01],
eta=.2)
model.lambdas = [[100, 100, 1e-16, 1e-16], [1e-16, 1e-16, 100, 100]]
documents = model.sample(100, 10)
# set alpha to wrong values
model.alpha = [4., 4.]
for i in range(100):
model.update_parameters(documents,
rho=.1,
max_iter_tr=0,
update_lambda=False,
update_alpha=True)
# make sure empirical Bayes went in the right direction
self.assertGreater(model.alpha[0], model.alpha[1])
self.assertLess(model.alpha[0], 4.)
self.assertLess(model.alpha[1], 4.)
def test_vi(self):
W = 100
K = 20
D = 10
N = 100
# generate random vocabulary
vocab = [
''.join(
choice(ascii_letters) for _ in range(5 + random.randint(10)))
for _ in range(W)
]
model0 = ReferenceLDA(vocab, K, D, 0.1, 0.3, 1024., 0.9)
model1 = OnlineLDA(num_words=W, num_topics=K, num_documents=D)
model1.alpha = model0._alpha
model1.lambdas = model0._lambda
# generate D random documents of length up to N
docs1 = []
for _ in range(D):
docs1.append([
(w, random.randint(10))
for w in random.permutation(W)[:1 + random.randint(N)]
])
docs0 = [zip(*doc) for doc in docs1]
# use the same initialization of gamma
initial_gamma = random.gamma(100., 1. / 100., [K, D])
gamma0, sstats0 = model0.do_e_step(docs0,
max_steps=50,
gamma=initial_gamma.T)
gamma1, sstats1 = model1.do_e_step(docs1,
max_iter=50,
latents=initial_gamma)
# make sure e-Step gives the same results
self.assertGreater(
corrcoef(gamma0.T.ravel(), gamma1.ravel())[0, 1], 0.99)
self.assertGreater(
corrcoef(sstats0.ravel(), sstats1.ravel())[0, 1], 0.99)